Add and list environment members

tests/models/test_environments.py

@@ -0,0 +1,16 @@
+from atst.domain.environments import Environments
+from atst.domain.workspaces import Workspaces
+from atst.domain.projects import Projects
+from tests.factories import RequestFactory, UserFactory
+
+
+def test_add_user_to_environment():
+    owner = UserFactory.create()
+    developer = UserFactory.from_atat_role("developer")
+
+    workspace = Workspaces.create(RequestFactory.create(creator=owner))
+    project = Projects.create(workspace, "my test project", "It's mine.", ["dev", "staging", "prod"])
+    dev_environment = project.environments[0]
+
+    dev_environment = Environments.add_member(owner, dev_environment, developer)
+    assert developer in dev_environment.users